<?php

/**

 * Class Name: wp_bootstrap_navwalker

 * GitHub URI: https://github.com/twittem/wp-bootstrap-navwalker

 * Description: A custom WordPress nav walker class to implement the Bootstrap 3 navigation style in a custom theme using the WordPress built in menu manager.

 * Version: 2.0.4

 * Author: Edward McIntyre - @twittem

 * License: GPL-2.0+

 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt

 */

class Magazine_Newspaper_Wp_Bootstrap_Navwalker extends Walker_Nav_Menu {

  /**

   * @see Walker::start_lvl()

   * @since 3.0.0

   *

   * @param string $output Passed by reference. Used to append additional content.

   * @param int $depth Depth of page. Used for padding.

   */

  public function start_lvl( &$output, $depth = 0, $args = array() ) {

    $indent = str_repeat( "\t", $depth );

    $output .= "\n$indent<ul role=\"menu\" class=\" dropdown-menu\">\n";

  }

  /**

   * @see Walker::start_el()

   * @since 3.0.0

   *

   * @param string $output Passed by reference. Used to append additional content.

   * @param object $item Menu item data object.

   * @param int $depth Depth of menu item. Used for padding.

   * @param int $current_page Menu item ID.

   * @param object $args

   */

  public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {

    $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

    /**

     * Dividers, Headers or Disabled

     * =============================

     * Determine whether the item is a Divider, Header, Disabled or regular

     * menu item. To prevent errors we use the strcasecmp() function to so a

     * comparison that is not case sensitive. The strcasecmp() function returns

     * a 0 if the strings are equal.

     */

    if ( strcasecmp( $item->attr_title, 'divider' ) == 0 && $depth === 1 ) {

      $output .= $indent . '<li role="presentation" class="divider">';

    } else if ( strcasecmp( $item->title, 'divider') == 0 && $depth === 1 ) {

      $output .= $indent . '<li role="presentation" class="divider">';

    } else if ( strcasecmp( $item->attr_title, 'dropdown-header') == 0 && $depth === 1 ) {

      $output .= $indent . '<li role="presentation" class="dropdown-header">' . esc_attr( $item->title );

    } else if ( strcasecmp($item->attr_title, 'disabled' ) == 0 ) {

      $output .= $indent . '<li role="presentation" class="disabled"><a href="#">' . esc_attr( $item->title ) . '</a>';

    } else {

      $class_names = $value = '';

      $classes = empty( $item->classes ) ? array() : (array) $item->classes;

      $classes[] = 'menu-item-' . $item->ID;

      $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );

      if ( $args->has_children )

        $class_names .= ' dropdown';

      if ( in_array( 'current-menu-item', $classes ) )

        $class_names .= ' active';

      $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

      $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );

      $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';

      $output .= $indent . '<li' . $id . $value . $class_names .'>';

      $atts = array();

      $atts['title']  = ! empty( $item->title ) ? $item->title  : '';

      $atts['target'] = ! empty( $item->target )  ? $item->target : '';

      $atts['rel']    = ! empty( $item->xfn )   ? $item->xfn  : '';

      // If item has_children add atts to a.

      if ( $args->has_children && $depth === 0 ) {

        $atts['href']       = $item->url;

        //$atts['href'] = ! empty( $item->url ) ? $item->url : '';

        //$atts['data-toggle']  = 'dropdown';

        //$atts['class']      = 'dropdown-toggle';

        //$atts['aria-haspopup']  = 'true';

      } else {

        $atts['href'] = ! empty( $item->url ) ? $item->url : '';

      }

      $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );

      $attributes = '';

      foreach ( $atts as $attr => $value ) {

        if ( ! empty( $value ) ) {

          $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );

          $attributes .= ' ' . $attr . '="' . $value . '"';

        }

      }

      $item_output = $args->before;

      /*

       * Glyphicons

       * ===========

       * Since the the menu item is NOT a Divider or Header we check the see

       * if there is a value in the attr_title property. If the attr_title

       * property is NOT null we apply it as the class name for the glyphicon.

       */

      if ( ! empty( $item->attr_title ) )

        $item_output .= '<a'. $attributes .'><span class="glyphicon ' . esc_attr( $item->attr_title ) . '"></span>&nbsp;';

      else

        $item_output .= '<a'. $attributes .'>';

      $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;

      $item_output .= ( $args->has_children && 0 === $depth ) ? ' <span class="caret"></span></a>' : '</a>';

      $item_output .= $args->after;

      $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );

    }

  }

  /**

   * Traverse elements to create list from elements.

   *

   * Display one element if the element doesn't have any children otherwise,

   * display the element and its children. Will only traverse up to the max

   * depth and no ignore elements under that depth.

   *

   * This method shouldn't be called directly, use the walk() method instead.

   *

   * @see Walker::start_el()

   * @since 2.5.0

   *

   * @param object $element Data object

   * @param array $children_elements List of elements to continue traversing.

   * @param int $max_depth Max depth to traverse.

   * @param int $depth Depth of current element.

   * @param array $args

   * @param string $output Passed by reference. Used to append additional content.

   * @return null Null on failure with no changes to parameters.

   */

  public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {

        if ( ! $element )

            return;

        $id_field = $this->db_fields['id'];

        // Display this element.

        if ( is_object( $args[0] ) )

           $args[0]->has_children = ! empty( $children_elements[ $element->$id_field ] );

        parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );

    }

  /**

   * Menu Fallback

   * =============

   * If this function is assigned to the wp_nav_menu's fallback_cb variable

   * and a manu has not been assigned to the theme location in the WordPress

   * menu manager the function with display nothing to a non-logged in user,

   * and will add a link to the WordPress menu manager if logged in as an admin.

   *

   * @param array $args passed from the wp_nav_menu function.

   *

   */

  public static function fallback( $args ) {

    if ( current_user_can( 'manage_options' ) ) {

      extract( $args );

      $fb_output = null;

      if ( $container ) {

        $fb_output = '<' . $container;

        if ( $container_id )

          $fb_output .= ' id="' . $container_id . '"';

        if ( $container_class )

          $fb_output .= ' class="' . $container_class . '"';

        $fb_output .= '>';

      }

      $fb_output .= '<ul';

      if ( $menu_id )

        $fb_output .= ' id="' . $menu_id . '"';

      if ( $menu_class )

        $fb_output .= ' class="' . $menu_class . '"';

      $fb_output .= '>';

      $fb_output .= '<li><a href="' . admin_url( 'nav-menus.php' ) . '">Add a menu</a></li>';

      $fb_output .= '</ul>';

      if ( $container )

        $fb_output .= '</' . $container . '>';

      echo $fb_output;

    }

  }

}